Every time the story starts getting engaging, up pops a pointless filler scene of rough-housing to slow the action down. Douglas Fairbanks, Jr.'s narration is the best element of the film, spoken with the appropriate levels of gusto, gravity and humor. This film would have been a good candidate for some judicious editing.

Compared to Fairbanks's "Three Musketeers," this is not so good. The sword fighting is better, but it seems all "out of focus." That might have been due to the knowledge that it would some sound, whereas "Three Musketeers" was a silent film. The acting seems less intense, more open to a new effect, and frankly it just doesn't work that well. Richelieu, for instance, in "Three Musketeers," was downright scary; he's more of a caricature here.
Mostly though, I think Fairbanks just wasn't as physically up to the role as he had been eight years earlier for "Three Musketeers." "The Taming of the Shrew" came out also in 1929, and that wasn't really very good, either.
That said, I like this movie. The ageing of the musketeers is done believably; and it is rather poignant, considering that Fairbanks Sr. didn't live long enough to grow very old. The relationship between D'Artagnan with the king is enjoyable, especially the little sword fight they have.
The last scene, which is quite famous, is also very moving. I especially like the four musketeers gazing down on the mourning court, and D'Artagnan enjoying it so much -- it's like Tom Sawyer and his gang enjoying their own funeral: eternal boyhood.
I have heard that there is an audio recording of Fairbanks Sr to go with this movie; that would be very enjoyable to watch.

a 1952 re-release , narrated by douglas fairbanks jr.-------a very appealing version that plays like a bedtime story you dont want to end. juniors voice is perfectly suited to the task of carrying us through this adventure . providing the exact amount of class-old world charm-and keeps us waiting for more. this version plays at a nice even pace , is visually decent, and is possibly better than the original (which has bit spoken parts in the beginning and three quarters through). a treat ----especially for youngsters who havent learned to read yet. plays well for everyone from four to ninety---what more could you ask for.

DOUGLAS FAIRBANKS///ALWAYS FUN//ALWAYS COOL

While still a fun movie, it should be noted that this is not the 1929 original "Iron Mask," but a reissued version created in 1952. The original 1929 version was made at the beginning of the sound revolution, and included only a few segments of narration.
In the reissue, the intertitles were removed and a narration was written by Richard Llewellyn (from the Elton Thomas story, which was in turn based on Dumas's Three Musketeers). The narration was read by Douglas Fairbanks, Jr., the son of the original actor.

This is an interesting and fun movie, and the story more believable than many of today's rehashed versions of the alexander dumas classic (there's even a shot of all four musketeers in bed together like sardines - which caused a chuckle considering that the scene in todays Hollywood would have been excised very quickly).
Basically it seems to be a silent movie, but dubbed with the voice of Douglas Fairbanks. I'd say the movie was released about the same time as sound recording emerged, and the movie re-edited to contain Fairbank's ongoing monologue - a voice that is still unique today.